The panel approved the measure by 10-8, supported by all Democrats and opposed by every Republican. Expanded background checks is the heart of President Barack Obama's proposals to curb firearms.

The sponsor is New York Democratic Sen. Charles Schumer.

He says the measure will reduce gun crimes. He also said he hopes he can strike a compromise on the measure with Republicans, which will enhance its chances of passing in the full Senate.

Iowa Sen. Charles Grassley is the top Republican on the panel. He says he believes the measure will ultimately lead to a federal registry of gun owners - which is illegal. Schumer said wouldn't happen.

THIS IS A BREAKING NEWS UPDATE. Check back soon for further information. AP's earlier story is below.

Democrats are ready to muscle expanded background checks and other gun curbs through a Senate committee, giving President Barack Obama an initial if temporary victory on one of his top priorities.

The Senate Judiciary Committee was to debate a bill Tuesday that would broaden the requirement for federal background checks to nearly all firearms purchasers. It was also considering a ban on assault weapons and an increase in federal aid for school security, though senators may not consider the assault weapons measure until later in the week.

Requiring background checks for private gun transactions between individuals - they're currently mandatory only for sales by licensed dealers - is a centerpiece of Obama's proposal to reduce firearms violence. The system is designed to prevent criminals, people with severe mental problems and others from getting guns.

Tuesday's meeting comes five days after the panel approved Congress' first gun control measure since December's carnage at a Newtown, Conn., elementary school that left 26 students and educators dead. That bill, by the Judiciary Committee's chairman, Sen. Patrick Leahy, D-Vt., and others, establishes long prison terms for illegal gun traffickers and straw purchasers, people who buy a firearm for criminals or others forbidden to buy one.

The Judiciary Committee is expected to approve all three bills it is debating this week, with full Senate consideration next month.

"The American people need to speak up and be heard," Leahy said Monday of what it will take for gun measures to clear Congress.

The background check bill by Sen. Chuck Schumer, D-N.Y., would exempt only a narrow range of transactions from the checks, such as those between immediate family members or weapons loaned temporarily during sporting events. It would also renew the requirement that states and federal agencies report records on felons, people with major mental health problems, drug abusers and others to the federal background check system - something that many states and agencies do poorly.

Schumer had hoped to win GOP support for his measure, and he spent weeks bargaining with conservative Sen. Tom Coburn, R-Okla., who carries an A rating from the National Rifle Association. Those talks foundered, and the measure the New Yorker is pushing seems sure to meet strong GOP opposition.